Remove Fake Transparent Background
There are many images with a fake transparency (white / grey checkerboard) in them. They are often JPG, or even PNG with no true transparency. It is very easy to get rid of that checkerboard pattern!
Go to Photopea.com, press File > Open, and open your image. Then, press Select > Magic Cut. You will see your image, and a final version next to it (if it is incorrect, look at our Magic Cut tutorial).
Confirm it with the "OK" button. Now, hit File - Export As - PNG, and you are done :)
Here is a GIF version.